Article shines a number of the main diseases of sunflower and a measure of fight against them.
On this culture 65 causative agents of mushroom diseases among which are most significant the white are registered and gray decayed, fomopsis, alternarioz, fuzarioz, false mealy dew
On this culture 65 causative agents of mushroom diseases among which are most significant the white are registered and gray decayed, fomopsis, alternarioz, fuzarioz, false mealy dew.
White decay or sklerotinioz – very harmful zaboleyovaniye – meets almost in all areas of cultivation of this maslichyony culture. The activator – Sclerotiniasclerotiorum mushroom (Lib.) Vagu’s de, a facultative parasite with wide specialization – strikes a podyosolnechnik during the entire periods it a razyovitiya. The illness is shown in priyokornevy, stem, korzinochny and is more rare – sheet forms. During the period from 1970 to 2004. proyavleyony white decay prinimalo character of an epifitotiya. Intenyosivnoye development of an illness was caused by the raised kolicheyostvo of a precipitation (in 1,5-2 times more norm) in June-September and ponizheyoniy daily average temperatures on 1,5-2 °C against mean annual rates.
The importance in decrease in a vreyodonosnost sklerotinioza has a crop rotation. Strict observance of term of return of sunflower and sowing not earlier than in four years lodge struck with this illness kultur (peas, a rape, mustard, a surepitsa, haricot) considerably reduces a stock of the infectious beginning sklerotinioza in the soil. Sowing of sunflower lodge peas leads to defeat of 25-30 % of plants, the crop thus decreases for 15-25 %, commodity and sowing qualities semyan worsen.
Seeds should be sowed in optiyomalny terms at soil warming up on depth of seal to 10-12 °C. Early terms of sowing privodyat to an izrezhivaniye of shoots and a razviyotiya of radical and stem forms of an illness, on late crops nablyudaetsya strong distribution of white decay at loss of an obilyyony precipitation at the end vegetacionnogo the period.
Before sowing seed material disinfect TMTD, a century (400 g/l) – 4-5 l/t, Maxim, ks (25 g/l) – 5 l/t, or rovraly, the joint venture (500 g/kg) – 4 kg/t. Reduce a vredoyonosnost sklerotinioza and a desikayotsiya of crops by a raglan super, vr (150 g/l) – 2 l/hectares or basty, vr (150 g/l) – 1,5-2 l/hectares at humidity of seeds of 30-35 %. At degree the illness razviyotiya on baskets more than 10 % is economically justified a desikatsiya by a raglan super – 2 l/hectares at humidity of seeds of 40 %.
After cleaning strongly struck sklerotiniozy crops of a podsolyonechnik it is expedient to crush the postharvest remains disk hoeing plows or disk boronami and in 15-20 days to plow with a layer turn. This reception sposobstvuet to faster a razlozheyoniya of the infected vegetative remains in the soil.
Gray decay at a mass porayozheniye can cause losses of 46-50 % of a crop. Seeds of sick rayosteniye are absolutely unsuitable for sowing.
The activator – an imperfect mushroom of BotrytiscinereaPers. Sunflower selection on stability to gray decay yet didn’t give appreciable results. All this very much complicates fight against a pathogen.
The temperature of 15-20 °C and otnoyositelny humidity of air of 85 % promote development of gray decay. The pathogen strikes shoots, stalks, chereshka and leaves, baskets, semena.
Actions for decrease in a porayozheniye by gray decay – the same, as against sklerotinioza.
In 1990 in Russia the new illness of sunflower – fomopsis for the first time was registered. Vozbuyoditel – PhomopsishelianthiMunt mushroom. – Cvet. etal. It strikes listya and chereshka, stalks and baskets. Inokulyum of the activator remains not only on the vegetative remains, but also on seeds. The basic istochniyoky primary infection yavlyayutsya askospor, which vybrasyvayutsya peritetsiya during the whole vegetative period.
For infection and development patogena are favorable high otnosiyotelny humidity of air and temperatura 20-28 °C. Lower than 5-7 °C and above 30 °C growth of a mushroom stops. A Bioyologichesky threshold of injuriousness fomopsisa sunflower – 5 % of the lost plants.
Effective reception in fight with fomopsisy is the obezzarayozhivaniye of seeds before crops vintsity, sk (25 + 25 g/l) – 2 l/t, kolfugo super, ks (200 g/l) – 1,5-2 l/t.
Sowing of sunflower should provoditsya in optimum terms and reyokomendovanny norm of seeding semyan for this zone. Zagushcheniye steblestoya with 40 to 80 thousand plants on 1 hectare sposobstvovetn to increase in distribution fomopsisa with 16 to 23 %. The sunflower fields, substantially struck foyomopsisy, after cleaning neobxodimo zadiskovat for crushing of the vegetative remains, and then zapaxat with a layer turn. At a vyyopolneniye of these receptions on the rastiyotelny remains peritetsiya aren’t formed, besides, they bystyory decay.
In recent years some mushroom diseases which earlier weren’t of great importance, raise a vreyodonosnost. Among them first of all it is necessary to mention alternarioz and fuzarioz sunflower.
Altarnarioz is called by nesoyovershenny mushrooms from the sort Alternaria, obnaruzhivaetsya on leaves and stalks in the form of spots of a various form and size, from dark to black-brown color. To pathogen development blagopriyatstvuyut rainy weather and plentiful dews. Immune grades to al-ternariozu aren’t present.
Essentially reduces illness manifestation a protravlivaniye of seeds. Alternariya development on commodity crops of sunflower of notable harm doesn’t put. It is dangerous to seed crops. Violation here technologies of cleaning sposobstvuet to defeat alternariozy a semyanka germ that leads to decrease vsxozhesti for 15-18 %. Cleaning of seed crops neobxodimo to carry out at humidity semyan 10-12 % with frequency a vrashcheyoniya of a molotilny drum of 300-350 rpm. Late terms of cleaning conduct to development of a sporonosheniye of a mushroom on baskets and to a zasporeniye of a seed material.
Search of chemical means of fight with the alternariozy proceeds. Are received encouraging rezultaty when using fungicidov, containing tebukonazol.
Causes alarm distribution increase fuzarioza. Bolezn it is observed annually. Activators – mushrooms from the sort Fusarium – cause decay of a basket, roots, rotting of seeds, shoots, withering of plants, defeat listev and stalks. Most vredonosny decay of a basket, roots and uvyayodaniye of plants.
Use of only nitric fertilizers for top dressing of plants leads to defeat strengthening fuzariozami. On rekomenyodatsiya VNIIMK their application should be balanced with fosyoforny in the ratio 1:1,5 or 1: 1. On soils with an insufficient soyoderzhaniye of potassium bring also this eleyoment.
Preseeding disinfecting of seeds of TMTD, eyelids (400 g/l) – 4-5 l/t promotes increase their poleyovy vsxozhesti at the expense of reduction of infectious loading. For a snizheyoniya of injuriousness of an illness on posevax sunflower it is necessary provodit all complex of agrotekhnichesyoky actions, including fight against weed vegetation, to increase natural stability of rasteyoniya to a pathogen by creation of komyofortny conditions for their growth.
The big rasyoprostraneniye was received by ashy decay. The activator – a nesovershenyony mushroom of SclerotiumbataticolaTaub. Symptoms of an illness appear in the second half of vegetation of a podsolyonechnik. In a butonizatsiya phase patogen gets in carrying out sistemu roots, and then in vascular siyosty stalks. The metabolism, water supply, voznikaet a lack of food elements is broken. Injuriousness is shown in a sniyozheniye of efficiency of plants and crop deterioration.
Distribution and development of peyopelny decay in considerable stepeni depend on a hydrothermal mode on years and even to separate months of the vegetative period when goes maximum potrebleyony waters plants. For skoroyospely grades it is June-July, for early and mid-season – July.
The grades deduced on the basis of interspecific hybrids, to a lesser extent are subject to defeat by ashy decay. The Sushcheyostvenny role in decrease in a rasprosyotraneniye of an illness play sevooborot, having sat down in optimum terms, a soyoblyudeniye of norms of seeding of seeds. Zaguyoshchennye crops (over 50 thousand rasyoteniye on 1 hectare) are surprised more strongly.
Annually on crops of a podsolnechyonik manifestation of dry decay is observed. Activators – the lowest mushrooms of the sorts Rhizopus. Stronger development of an illness is observed at dry and hot weather during the period from flowering before cleaning. Sporangium rasprostranyayutsya wind, birds and insects.
Thanks to successful work of seyolektsioner considerably sokratilas injuriousness on a podsolnechyonik of a rust, false mealy dew, zarazixi, verticilleza, kotoyory earlier caused an essential loss to a crop. However in connection with a poyoyavleniye of new aggressive races of pathogens at non-compliance with a tekhnoyologiya of cultivation cases of increase and even the mass outbreaks of these diseases on earlier usyotoychivy grades are observed. One of the most rasprostyoranenny and harmful in the past of diseases of sunflower – rzhavchinu – it was possible to selectors nejtralizovat.
The last 15 years the majority of grades and hybrids of sunflower possesses field stability and to false mealy dew. However because of emergence in population patogena new, more virulentny races threat of emergence of an epifitotiya remains.
Great value for protection of sunflower against mealy dew the crop rotation, term vozvrata have cultures on a former place (not earlier than 8 years), destruction padaliyoets. It is not necessary to sow a podsolnechyonik earlier, than in 2 years after deeply taking roots cultures, especially sugar beet; razmeshhat crops near fields, on koyotory the sunflower was grown up in previous year. Seeds sortov and the hybrids which are not possessing an usyotoychivost to an illness, before sowing it is necessary to process aprony Gold, ve (350 g/l)-3 l/t.
Vertitsillez (the activator – a neyosovershenny mushroom of VerticilliumdahliaeKleb.) – is one of dangerous diseases of sunflower. At early infection of a plant perish and don’t give a crop, at boyoly late – the size of a basket decreases, the crop of seeds decreases, their luzzhistost, snizhaetsya the content of fat in a kernel increases. The illness is shown in flowering of plants. At the expense of poluyochenny the method of an interspecific gibyoridizatsiya of grades possible to reduce injuriousness of a zayobolevaniye znachiyotelno. In many countries sorta selections VNIIMK use in selection programs as an isyotochnik of stability to this vozbuyoditel.
The changes occurring in a popuyolyatsiya of a pathogen, reduction obemov a protravlivaniye of the seeds, the extremely limited rotation of a podsolnechyonik in a crop rotation, weather an usloyoviya become the reason of defeat of grades vertitsillezy. For suppression of increase of a rasyoprostraneniye of a vertitsillezny uvyayodaniye it is necessary obligatory burning of the infected vegetative remains after cleaning of a podsolnechyonik, crop rotation observance, destruction of weeds, collecting seeds on seed sites only from zdoyorovy plants.
Sunflower common people, or fomoz (the activator – a piknidialny mushroom of PhomaoleraceaeSacc.), nesmotrya on quite high rasprostrayoneniye, doesn’t render essential influence on a crop and sowing kacheyostvo of seeds. Weather conditions sposobstvuyut to late infection of rayosteniye fomozy, usually in phases of flowering, maturing as the znachiyotelny part infectious nachala during the winter period perishes. In the spring because of high temperatures and neyodostatochny amount of moisture spory a mushroom quickly lose a zhiznespoyosobnost, education and sozrevayony new piknid is late, and plants aren’t exposed to early infection. Usual rekomendayotsiya on technology of cultivation of sunflower allow not primenyat against this disease of special measures of fight.
(On magazine materials Protection and quarantine of plants).