Article InfoOver the years, the use of organic materials in farming has reduced due to the increase in the use of chemical fertilizers which are rich in readily available plant nutrients. Intensive use of chemical fertilizers may have depressing effect on yield of watermelon. The field experiment were conducted at the Experimental Clinic of the Laboratory "Selection of vegetable and melon crops" and in the laboratory "Biosafety and Biocontrol of vegetable and melon crops" of Regional Branch "Kainar" of the LLP "Kazakh Research Institute of Fruit and Vegetable Growing" which is located in the foothill zone of the southeast of Kazakhstan, to study the effects of different types of organic fertilizers (cow manure, poultry manure and biohumus) and recommended chemical fertilizer (NPK) on the characteristics of watermelon (growth parameters, yield and quality) of southeast of Kazakhstan. There were significant differences among the treatments in relation to fruit yield of watermelon, growth paremeters and quality properties (dry matter, total sugar, Vitamin C and NO3-N). Recommended fertilizer dose (N90P60K60) had the highest fruit yield of watermelon and growth paremeters followed by manure applied at 40 t ha -1 . All the fertilizer treatments had higher yield of watermelon than control. From this study, the use of manure as an organic fertilizer in the cultivation of watermelon could be used as alternative to chemical fertilizer. It is recommended that manure at 40 t ha -1 be adopted for watermelon cultivation in in the Southeast of Kazakhstan.

In Kazakhstan, melon growing is cultivated using chemical fertilizers. Organic production is not practiced where there being no research. Our country, possessing a great high-quality variety, can be the focus of world community attention as a producer and supplier of ecological melon. Besides economic interests, changeover from traditional methods of cultivation to biological one is of great importance in ecological aspect. Unregulated and too high agrochemicals application causes a number of negative consequences, upwards from soil pollution with severe salts to poisoning caused using low-quality products. The most popular and regulated elements of biological melon cultivation in production include organic fertilizers instead of chemical ones. Therefore, our research is aimed to study bioorganic fertilizers on melon culture under Southeastern Kazakhstan. Scientific experiments were held at the experimental sites of the «Fruit and Vegetable Research Institute» LLP. We experimented using classical research methods generally adopted in melon cultivation. The findings showed that bioorganic fertilizers improve the growth parameters and quality of melon culture, and increase fruit productivity. The yield growth on the studied options for control ranged from 31.23% to 41.71%, depending on the nutritional conditions.

The results of the ecological variety testing of melon and watermelon hybrids are presented in the paper. In the period from 2018 to 2020, 10 foreign varieties and hybrids of melon and watermelon were evaluated according to economic and valuable characteristics in the adaptation nursery in the climatic conditions of southeastern Kazakhstan. According to the set of qualities and indicators, 4 melon and watermelon varieties were distinguished and suggested for production.