<div>Background: Avian tongue has a significant role in the feeding process. The current investigation was planned to study the histological and ultrastructural features of the tongue in two avians. Java sparrow (Lonchura oryzivora) and Hoopoe (Upupa epops).&nbsp; 
 
Methods: Fourteen birds were used including seven Java sparrows and seven Hoopoes during the current investigation. Careful procedures were used in the dissection process of the two avian species. Their heads were separated and four tongue samples (from each species) were taken to fixed in 10% buffered formalin for histological observations.&nbsp; 
 
Result: Histologically, the lingual glands in Lonchura oryzivora were simple-branched acinar and compound acinar. Whereas, the lingual glands in Upupa epops were simple acinar and simple-branched acinar. Three tongue samples (from each species) were taken to fixed in 2.5% of glutaraldehyde for the ultrastructural observations. The SEM findings in both species showed main three parts of the tongue; apex (anterior part), corpus (middle part) and radix (posterior part). Lonchura oryzivora&lsquo;s tongue has an elongated dart form with anterior terminal curved pointy conical papillae. Mid-dorsal trench (Sulcus medianus) extended from the apex to the anterior region of the radix. While the tongue of Upupa epops was triangular form with a convex tip and it has a V-form papillary crest. The observed findings of the histological and ultrastructural dissimilarities of Java Sparrow and Hoopoe emphasized more insight into the feeding behaviors and adaptation of the two avians.</div>

Comparative Histological and Ultrastructural Studies on the Tongue of Two Avian Species (Lonchura oryzivora and Upupa epops)

Background: A field experiment was conducted during the rice fallow season of 2023 and 2024 (January to March) at Tamil Nadu Rice Research Institute (TRRI), Aduthurai, Tamil Nadu to study the residual effect of rice-fish-based organic nutrient management practices adopted in rice on succeeding blackgram grown as rice fallow. 
 
Methods: The experiment was carried out using randomized block design (RBD) with eleven treatments viz., T1- No Green manure-Rice crop alone (RDF), T2-Green manure- Rice crop alone (PSB+KSB+ZSB), T3-T2+Nanourea, T4-Green manure- Rice crop (PSB+KSB+ZSB) + Fish, T5-T4 + Nano urea,T6- Green manure- Rice crop (PSB+KSB+ZSB) + Fish + Azolla, T7-T6 + Nano urea, T8-Green manure-Rice crop (PSB+KSB+ZSB) + Fish + Duck, T9- T8+Nano urea, T10- Green manure- Rice crop (PSB+KSB+ZSB)+ Fish + Azolla + Duck, T11- T10+Nano urea. The treatments were replicated thrice. The blackgram variety ADT 6 was used as a test crop. 
 
Result: The results revealed that among the different organic nutrient management approaches followed in the rice-fish based farming system, the residual effect of Green manure- Rice (solubilizing bacteria such as PSB, KSB and ZSB) + Fish + Azolla + Duck (T10) resulted in higher plant height, DMP, LAI and SPAD value in blackgram. Similarly, the highest root length (19.43 cm), root dry weight (1.10 g), root volume (10.68 g/cc), nodule plant-1at 20 DAS (13.82) and nodule plant-1at 40 DAS (22.97) were also obtained with the same treatment. By virtue of higher growth and yield parameters, more number of pods plant-1 (26.88) and seeds pod-1 (7.73), grain yield (789 kg ha-1) and Halum yield (2136 kg ha-1) of blackgram were obtained in the residual treatment of the residual effect of Green manure- Rice (solubilizing bacteria such as PSB, KSB and ZSB) + Fish + Azolla + Duck (T10). The available soil nutrients at 20 DAS of blackgram were higher in Green manure- Rice (solubilizing bacteria such as PSB, KSB and ZSB) + Fish + Azolla + Duck (T10). Due to higher blackgram yield, the same treatment achieved higher gross return (Rs.41561 ha-1), net return (Rs.30156 ha-1) and BCR (3.64). The study also indicated that the trench (300 m3) dug in rice fields for fish rearing provided sufficient moisture for rice fallow blackgram and thereby evaded the terminal stress.

Residual Effect of Rice-fish Based Organic Nutrient Management Approaches on Rice Fallow Blackgram Productivity Enhancement in Cauvery Delta Zone of Tamil Nadu