Performance of Trichoderma-enriched bio-organic fertilizer in N supplementation and bottle gourd production in field condition

Excessive inorganic fertilizers and plant protection chemicals usages in crop production induce risks of both human health and environment. Besides, generally 50% of N and 90% of P from applied inorganic fertilizers are fixed up in soils and run off, and ultimately it releases into atmosphere and water sources, which contribute for greenhouse gas generation, eutrophication and soil salinization.1,2 Application of excessive P induce cadmium in soil that come to food chains.3 Moreover nitrogen application increase nitrates in ground water which are finally responsible for N-nitroso compounds and ultimately often linked with fatal methemoglobinemia.4 To minimize these problems the relevant researchers have been trying to develop sustainable safe and environmental friendly technologies that will help to minimize usages of chemical fertilizers for crop production. Accordingly Trichoderma spp. enriched bio-organic fertilizers; pellets and suspension are being evaluated to monitor its performance in different crop production.5‒7 In recent years it has achieved recognition as plant growth promoter, enhanced antioxidant compounds,7,8 increased yield of several crops in field condition.6,10‒12 Besides, some Trichoderma rhizosphere-competent strains have been shown to have direct effects on plants, increasing their growth potential and nutrient uptake, fertilizer usage efficiency, percentage and rate of seed germination, and stimulation of plant defense against biotic and abiotic damages.13,14 Trichoderma metabolites and roots colonization by Trichoderma change the proteome and transcriptome of plants,15,16 which enhance plant growth and development but these mechanisms of Trichoderma plant interaction are not quite easy. Application of Trichoderma fungi ensures the favorable environment for growing and proliferation of abundant healthy roots and simultaneously plant derived sucrose which is an important resource provided by the Trichoderma spp. Cells.17 Thus plants become benefited from this relationship through increased root and shoot growth and increased macroand micronutrient uptake. Therefore, Trichoderma spp. are being treated as growth promoting (bioorganic fertilizer) as well as pathogen control agent (mycofungicide) and their application may lower the production cost of crops along with conserving congenial environment. Vegetable cultivation is one of the most important and dynamic wing of agriculture in Bangladesh. Among the cultivated vegetables in Bangladesh, bottle gourd (Lagenaria spp.) a cucurbit is a popular crop has now drawing attention to greater extent. Bottle gourd (Lagenaria spp.) is a common and delicious winter vegetable in Bangladesh. Generally bottle gourd fruits are used as fruit vegetable, but its leaves tender stem are used as delicious and nutritious leafy vegetable.18 It is reported as an easily digestible vegetable which keeps the body cool and prevents constipation. Its cultivation and usages are wide in winter but now a day it is cultivating during summer and rainy season also. Bottle gourd is vine crop grow rapidly and their stem become 10-12 meter long which generally need support to climb by the pole along the stem. It prefers well-drained, moist, rich soil and proper fertilizer management practices for successful crop growth and yield.19 At this situation, slow release nutrient rich fertilizers/compost/bio-organic fertilizer might contribute significant roles for bottle gourd cultivation. Bio-organic fertilizer is defined as the fertilizer contained living cells or latent cells of efficient strains of microorganisms with decompose