DEVELOPMENT OF PRODUCTION TECHNOLOGIES FOR MILKY WHITE MUSHROOM (Calocybe indica) CULTIVATION IN BANGLADESH

Abstract

The present research work was conducted to identify suitable strains and develop appropriate production technologies for commercial cultivation of milky white mushroom in Bangladesh. To satisfy the objectives, eight different experiments were conducted in Mushroom Development Institute, Savar, Dhaka, Bangladesh during 2018 to 2020. In the first experiment, performance of four strains of milky white mushroom Cid-1, Cid-A, Cid-In and Cid-S were evaluated during three growing seasons in a year. Among the strains Cid-1 performed better during summer and rainy season and Cid-A during autumn season. Whereas, performance of strain Cid-S was worst during all the growing season. DNA finger print showed that the four strains were genetically different from each other. In the second experiment nine different combination of substrates were evaluated to identify suitable substrate for milky white mushroom cultivation. Results revealed that, economic yield (427.33 g/packet) was highest in rice straw + sawdust (1:1) substrate followed by rice straw along (352.00 g/packet) on the other hand it was lowest in sawdust + wheat bran (2:1) substrate (264.05 g/packet). Wide variation was observed in nutrient content of fruiting body grown on different substrates. Eleven different combination of casing materials were evaluated in the third experiment. Results indicated that, coconut coir dust + decomposed cow dung (1:1) was the best and coconut coir dust alone was the worst performing casing material. Among different sterilization and spawning methods, hot water treated substrate spawning both in three layers and thoroughly performed better. Different moisture levels of rice straw substrate viz; 35, 40, 45, 50, 55, 60, 65, and 70 percent were used to determine appropriate moisture level of the substrate in the fifth experiment. It was observed that mycelium colonization was faster (14.5 days) at 70% moisture and no mycelium colonization at 35% moisture level. No substrate contamination was observed at 65% and 70% moisture level. Highest yield (361.1g) was recorded at 70% moisture level which was similar to 60% (315.2 g/packet) and 65% (303.8 g/packet) moisture level. In the sixth experiment five different techniques of casing material management were practiced and observed that, removal of dried non effective fruiting bodies after each harvest produced highest number of effective fruiting bodies (8.83) and number of flushes (2.81) but the economic yield and biological efficiency was not insignificantly affected by casing material management technique. To determine appropriate spawn density, 10, 20, 30, 40 and 50 percent rice grain spawn (dry weight basis) was used to inoculate rice straw substrate in the seventh experiment. Results revealed that partial mycelium colonization in spawn packets problem was completely disappeared with the increase of spawn density. Shortest time was required to complete spawn run (12.90 days) and primordia initiation (9.58 days), highest number of effective fruiting body (9.10) and number flushes (3.10), highest economic yield (454.88 g/packet) and biological efficiency (109.61%) were recorded at 50% spawn density but benefit cost ratio (3.83) was highest at 40% spawn density. To determine appropriate harvesting age of fruiting body for getting maximum yield and longer shelf life of milky white mushroom, fruiting bodies were harvested at 5 to 14 days old and stored in refrigerator and ambient condition- in open tray, cellophane wrapped tray and polypropylene bag. Results revealed that the highest number of effective fruiting bodies (9.15) were recoded from five days aged fruiting body harvest but average weight of fruiting body (63.35 g) and economic yield (483.13 g/packet) were highest at eight days harvest. The appearance and odor score of fruiting body decreased after nine days aged and lost its acceptability for consumption after thirteen days aged. The mushrooms lost its acceptability rapidly when it was stored in an open tray than cellophane paper wrapped tray and polypropylene bag both in refrigerator and in ambient condition. Within six days of storage at ambient condition milky mushroom lost its acceptability irrespective of fruiting body age and storage method. In refrigerator six to nine days aged fruiting body stored in cellophane paper wrapped tray and polypropylene bag was remained in good condition for consumption even after 15 days of storage.