Barley pests

A sound crop rotational system is of basic importance to the organic farmer. It reduces the risk of diseases and pests associated with monoculture, gives better control of weeds, spreads the labour requirements more evenly over the year, reduces the financial risk if one crop yields or sells badly and provides more interest for the farmer. For instance, take-all is a disease that cannot even be controlled chemically. Winter crops are more susceptible to take-all than spring sown crops and wheat is more susceptible than barley, so the safest position for winter wheat is immediately after a break crop. 

Proteolytic enzymes Animals, including insects and other arthropods or their larval forms Dusts from barley, oats, rye, wheat or maize, or Biological washing powders and the baking, brewing, fish, silk and leather industries Research and educational laboratories, pest control and fruit cultivation The baking or flour milling industry or on farms... 

It is very fortunate for the rice producers of the United States that rice, as compared to most crops, is relatively free from insect pests. Metcalf and Flint (2b) list 30 species of insects as being injurious to corn, 20 to wheat, rye, and barley, 31 to leguminous crops, and 23 to cotton, as compared to but 4 for rice. The fact that rice fields are flooded a large portion of the growing season results in ecological conditions unfavorable to numerous insects that otherwise would probably attack this crop. 

Several plant defensins have also been found to be inhibitors of various enzymes in plant pests. The plant defensins Slctl, SIo 2, and SIa3 were the first plant defensins where inhibition of a-amylase was shown at low concentration whereas purothionins inhibited a-amylase activity only at high concentrations. Blal and BIa2 isolated from barley are two more representatives of proteinaceous a-amylase inhibitors in the plant defensin family. ... 

A crop rotation plan must be in place to protect against pest problems and to maintain soil health. Row crops should be raised for no more than four out of five years, and the same row crop cannot be grown in consecutive years on the same land. Legumes (e.g., alfalfa, red clover, berseem clover, and hairy vetch) alone, or in combination with small grains (e.g., wheat, oats, and barley), should be rotated with row crops (corn, soybeans, amaranth. 

Crop. ProL Confi -Pests Dis. 1977, 593 R. G. Harris et al, ibid. 1979, 53. Efficacy against cereal powdery mildew D. M. Weigh ton et al, ibid. 1977, 25. Protective effect against blotch in winter wheat and barley R. G. Harris, G. Barnes, ibid. 1981, 267. Effect on cytochrome P-450 and sterol biosynthesis in Japanese quail J.-L. Riviere et al, Pestic. Sci. 15, 317 (1984). Review A. de Seint-Blanquat, J. My, Def. Veg. 37, 121 (1983). 

Time of sowing can be very important for reducing pest problerrrs. Cereal growers in high-risk areas normally drill winter cereals after the rrtiddle of October to reduce aphid attack arrd trarrsfer of barley yellow dwarf virus (BYDV). MairKrop carrots are sown at the end of May or in early Jrme to avoid the first generation of carrot fly. 

The main pest problem which requires control, particularly in early-drilled winter barley, is to reduce barley yellow dwaifvirus transmitted by aphids (Table 7.1). In very susceptible areas the seed should be treated with clothianidin or an aphicide shorrld be applied at the end of October to the emerged crop. Early-drilled crops may reqrrire two apphcatiorts. 

Affects wheat, barley and some other grasses. This pest is very occasionally a problem in some of the more intensive cereal growing areas on heavy soils in the UK. 

In the works of A. Konarev (Konarev et al. 1999 Konarev et al., 2004) shows in detail the variability of inhibitors of trypsin-like proteinases in cereals due to resistance to various grain pests. So in wheat trypsin inhibitors are represented by several genetically independent systems of proteins controlled by the genome and B chromosomes ID (endosperm), 3Dp (aleurone layer), IDS and 3Ap (leaf). Trypsin inhibitors of rye are controlled chromosome 3R and barley 3H. The most complex structure of inhibitors was wheat leaves, with the genomic formula AABBDD. In general, it is the sum of the spectra of trypsin inhibitors from several tetraploid (T. turgidum) (AABB) and (Aegilops tauschii Coss.) (DD) (Konarev, 1986 Konarev et al., 2004). 

H. Buohenauer and E. Rflhner, Effect of triadimefon and triadimenol on growth of various plant species as well as gibberellin content and sterol metabolism in shoots of barley seedlings. Pest. Biochem. Physiol. 15 58 (1981)... 

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