Efficiency of chemical protection of spring rape and mustard from rape blossom beetle

One of the most dangerous pests of cabbage crops which can damage plants in the budding and flowering phases in all areas of their cultivation is a rape blossom beetle (Meligethes aeneus Fabricius, 1775). The pest is widespread throughout Ukraine; it causes significant damage to the crops every year and reduces the seed yields. It should be noted that the rape blossom beetle is not new to our country and as a pest of rape and other crops from the cabbage family has been mentioned since 1845, and a detailed description of its morphology, biology and ecology can be found in the works of the nineteenth century. It is established that in the Eastern Forest-Steppe of Ukraine the first individuals of the rape blossom beetle appear on the flowering wild growing plants (first of all on dandelion and buttercup) when the average daily temperature exceeds 8 °C, it is the middle of the first decade of April and the beginning of the third decade of April. The mass emergence of the rape blossom beetles takes place when the daily average temperatures are at the range of 9–13 °C and the sum of the effective temperatures above 5 °C is at the range of 100–113 °C, it is the middle of the second decade of April and the end of the third decade of April. The females of the rape blossom beetle usually lay 2–3 eggs into one bud of spring rape or mustard. When protecting the crops from the rape blossom beetle the highest technical efficiency was noted when applying the binary mixture of the microbiological preparation Actophyte, 0.25 % of emulsion concentrate in the dose of 4.8 L/ha and systemic insecticide Biscaya, 24 % of oily dispersion (0.25 L/ha) and in 14 days after spraying it was 76.6 % on white mustard, 74.3 % on Chinese mustard and 76.2 % on spring rape. The highest growth increase in the yield capacity was observed in the same variant; for white mustard it was 0.431 t/ha, for Chinese mustard it was 0.265 t/ha and for spring rape the growth increase amounted to 0.277 t/ha. As a result of the researches it is established that the weight of 1000 healthy seeds is 2,6996 g, and the weight of the seeds damaged by the larvae of the rape blossom beetle is 0.4213 g, so it is reduced by 84.4 %. The filling of the damaged seeds is 6.8 times more, which indicates that they are smaller in diameter and frail. The undamaged seeds of spring rape contain 35.92 % of fat, and the damaged seeds contain only 17.48 %, which is 2.05 times less. The protein content in the undamaged seeds was 30.97 % and in the damaged ones it was 32.23 %, that is 1.04 times more. The germination rate of the undamaged seeds of spring rape under the laboratory conditions on the eighth day was 90.0 %, and the germination rate of the damaged ones amounted to 58.0 % and was lower by 32.0 %.

HYGIENIC SIGNIFICANCE OF THE DETERMINATION OF PESTICIDES IN SEDIMENTATION TESTS

Introduction. The use of pesticides creates the danger of contamination of the soil as a result of demolition outside the treatment area, which is assessed by comparing the actual pesticide content in the soil (mg/kg) with the maximum allowable / estimated allowable concentration (MAC/APC). Methods for the quantitative determination of pesticides in soil are labor-intensive; an alternative method for them may be an indirect method - determining the amount of drift to the soil using sedimentation samples (sedimentation - subsidence). The purpose of the study is a hygienic estimate of the amount of propiconazole deposited on the soil outside the cultivated area. The research objectives are to determine the content of propiconazole in the atmospheric air and on the soil outside the treatment area; to give a hygienic assessment of the amount of substance detected. Material and methods. Air samples were taken on aerosol paper filters, soil contamination was assessed using sedimentation samples by measuring the amount of substance deposited on the filters (about 40 cm2) in Petri dishes placed on the leeward side of the processing area. Results. Propiconazole was found in sedimentation samples at a level of 0.012-0.484 mg/m2 and was not identified in atmospheric air. Discussion. An algorithm is proposed for recalculating the results of measurements in filters for filters (mg/m2) for soil concentration (mg/kg), taking into account information on the mobility of the substance and the bulk density of the soil. It has been established: when using the drug in the form of an emulsion concentrate on field crops, the amount of propiconazole in demolitions on the soil can exceed the APC up to 10 times; the drug in the form of a nanoemulsion concentrate on garden crops ODC exceeded 17 times. The increased content of the substance in the soil is the reason for prohibiting the use of the drug using this technology. Conclusions. Sedimentation tests, being cumulative, confirm or refute the results of analytical control of atmospheric air, increasing the reliability of hygienic studies, further guaranteeing the safety of pesticide use for the population.

Observations on the peri-domestic breeding behaviour and resting sites of Glossina tachinoides Westw. near Nsukka, East Central State, Nigeria

In 1964–65, breeding sites of the tsetse fly G. tachinoides Westw. near Nsukka in south-eastern Nigeria were found in peri-domestic situations (particularly beneath stacked coco-yam tubers and at the base of fences of pig enclosures) and in adjacent farmland (particularly beneath banana and coco-yam plants, under Lantana camara, at the base of farmland fences and around derelict farm buildings). Between them, these sites provide moisture conditions suitable for year-round breeding of G. tachinoides and are not exposed to unsuitably high temperatures (>90°F) for long periods. The night-time resting sites of G. tachinoides in three villages five miles east of Nsukka were sought between May and November 1966 using ordinary torchlight. The most popular resting-sites were dried fronds of oil and coconut palms used for fencing pig enclosures, but a few flies also rested on man-made objects in the villages and on vegetation nearby. Most flies were resting less than two feet above ground level. Day-time observations confirmed the night-time findings. G. tachinoides could probably be controlled, if not eradicated, in the Nsukka area by two applications, a fortnight apart, of DDT emulsion concentrate to pig enclosure fences and pig styes up to a height of 2–3 ft during March–May when the fly population is most concentrated around confined pigs.

INEFFECTIVENESS OF THE OVERHEAD-IRRIGATION METHOD FOR THE APPLICATION OF INSECTICIDES TO CONTROL THE SUGARCANE MOTH STALK-BORER, DIATRAEA. SACCHARALIS (FABRICIUS)

The use of the overhead-irrigation system established at Colonia Juana Díaz, near Central Cortada, Santa Isabel, P. R., makes possible the application of fertilizers dissolved in water, and of insecticides for the control of soil-insect pests. Experiments were conducted during the crop years 1950 and 1951, using the overhead-irrigation system as a means of applying insecticides, in an attempt to control the sugarcane moth-stalk borer, Diatraea saccharalis (Fabricius). Thirteen different kinds of insecticides, namely: Aldrin, Chlordane, Dieldrin, Ryania, Rhothane (DDD), Benzene hexachloride, CPR Emulsion Concentrate, Gy-phene (Toxaphene), Muriate (Methoxychlor), Kryocide (natural cryolite insecticide), Dilan 25 EM, Heptachlor 2E Emulsion Concentrate, and Dr. Wolf's Insecticide A, were used. Each insecticide was applied at two different concentrations. Thirty-one plots planted with sugarcane, each having an area of 214 acres, were used in the experiment, 20 of them being treated with insecticides and 11 being used as checks. The insecticides were applied at 15-day intervals; there were four sprayings during each season. The experiments were initiated during the fall of 1950 and 1951, respectively, when the sugarcane plants were still small and had just begun to develop the first joints at the base of the stalks. The tables and analyses of the work conducted demonstrated that these insecticides, at least when applied by this method of spraying, were completely ineffective in the control of the insect. In many cases the check plots showed less borer infestation than those treated with insecticides; in others, the insecticide was more effective at low concentration than when used at twice that concentration. The ineffectiveness of the insecticides might be due, in part, to the large amount of water used which reduced the concentration of the chemical so much as to make it valueless in controlling the moth-borer.