engleski

Paprika weed control in unfavorable climatic conditions

On the basis of the two year investigation (2000 and 2001) of the industry hypogley paprika weed control carried out by chemical and mechanical measures it was determined that paprika growing from the field seed is under the question due to much crop weed occured under the inconvenient drought conditions in the spring-summer period and low efficiency of the applied herbicides. The weed control method under the particular climatic conditions was based on the assumption that the soil preparation for the seeding should be carried out 10 days prior to the seeding. In that way it would be possible to provoke weed emergence whereas paprika emergence from the seed requires 15 days to occur in the field conditions. This enabled total herbicides application in the weed control during the early emergence stage (2-4 leaves) prior to paprika emergence unlike application of the standard soil herbicides (prior to the seeding or directly after seeding) which showed insufficient effect in the later drought conditions. Also, mechanical weed control should have been carried out earlier, regardless herbicides application due to faster weed growth in unfavourable climatic conditions concerning paprika. Herbicides application in stripes combined with interrow cultivation presupposes both economic and ecological interest. Seeding of the cultivar KM-622 (Kolotchay-Morzar) was accomplished on 20 April in the both years , pre-emergence herbicide application 10 , hoeing 30 and 60 days after.The herbicides napropamid, pendimetalin, prometrin, dikvat and parakvat were single applied all over the area and in half dose in rows combined with interrow cultivation. Efficiency of the experiment members was determined via the combined estimation of the weed species number and vegetation (Braun- Blaquete, 1964), as well as final paprika yield. Prevailance of the annual late spring teraphytes (heliophytes) was detrmined in the 2000th year.. Thus, the largest vegetation of the species Polygonum lapathifolium (2750), subdominant species Anagalis (419) and Helianthus anuus (250) was found out in the 2000 whereas Matricaria chamomilla (3375), Amaranthus hybridus (3065) and Polygonum lapathifolium (2752) were dominant species in 2001. The above mentioned was determined by the phytocoenological checkings on the unhoed controls (in June and July). The herbicides effect on the weeds and paprika yield was the result of the series of dominant climatic conditions (plentiful precipitations and low temperatures during the germination and emergence period followed by the drought and hard crust formation in both years). A warm period at the beginning of June was favourable to a fast weed flora development especially to the late spring species when only a soil herbicide prometrin (Prohelan-T, at a dose of 3.0 l/ha with KE=99.76% ) showed a satisfactory effect in 2001. The best results in both years were showed by the repeated interrow hoeing free of the herbicides (KE=99.76% in 2000 and 99.68% in 2001) Thus, the highest paprika yields were obtained in the experiment members with two hoeings (1.115 kg/10 plants in 2000 and 1.743 kg/10 plants in 2001) and contact herbicides application (dikvat and parakvat) immidiatelly after weed emergence (prior to paprika emergence) with two interrow hoeings. Finally, this method is still under the question regarding industrial paprika production on larger areas due to unpredictable climatic changes in the investigation field for example precipitations that can prevent timely machinery application and cause even more intensive crop weed growing during the most sensitive early vegetation period.

paprika ; chemical and mechanical weed control

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