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19854
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Subject: Agronomy × Author: KAU × End date: 1985 × Start date: 1985 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Effect of NPK on seed progeny and air layers in cashew ( Anacardium occidentale L. )
    (Department of agronomy, College of Agriculture Vellayani , Trivandrum, 1985) Harishu Kumar, P; KAU; Sreedharan, C
    An experiment was conducted to assess the "Ef f e c t of NPK fertilisers on seed orogeny and air layers in cashew at Cashew Seed Farm, Shanmtigodu under Central Plantation Crops Research Institute , Regional Station, f i t c a l 574 24 3, during 1982-84. fhe treatments consisted of test ing three le v e ls each of d,? and K on seed . rogen/ i.,d ai r layers Ln cashcv/. r ’ne study revc ile 1 t h . t d i f f e r en t grov.'th oar meter 7 i. e . , he L'jl'it, can>py rolLus, surf ice area, le a f area n ; : ; v/erc influenced by increasing le v e ls of I:PR. f ■ r t i I i. s e r s . [' r/ ii chlorophyl l , to I; il v.ug ir , le.it v; .ter f-,■ n* , in-: sp e c i f ic le if w ight v;ere influenced by » b ,n v/11 i I e n i t rci' p n 11 one i n c i i iset i , , ., ii c * * . I', i r 1 y i'ii s r: u I: i- c ’ i I i r r - • * * in f l o w e r i n g , numbt l r, f ft mi. t e, _ .m ,lg ,■ I ; -I -,l puilr-h t'< t-i.l il 'hoots WC IX ; i ? V i . r ‘ I i I -■ 1 nr r r 1.0,1 b y f.f r » i I i d L >n . t’rmt j;un ii r‘ rc rn> r ri o nl; inrl acc' u b i ^ ici-1 c o n t e n t , ] Lc if ion . /c r | , 7 0 1 1 0 ' J W l ! " l p l Mut v Jupic an 1 IglTt wctr drrrc ir.ecl due to d M M, ion w,lH. V ipol ic .Llon ( ivour* rl nut md P i p d i ' - 1 , 4-r d W- i n ( k c - T l u 1 n - Leaf N v;as increased by NPIC. Lear ? was increased by p and K appl icat ion v/hile i t was reduced by N appl icat ion. Leaf K was reduced by H appl icat ion while i t was increased by ? and K appl icat ion. N appl ication resul ted in an Increase in le a f C i, where as P and K reduced i t . M and K reduced le a f Mg while P had no e f f e c t . M increased lui f Zn while P reduced the same. K had no e f f e c t . Cr i t ical levels in Ic if for M and ? are f ixed at 2.09% and 0.14% respectively. hoot CSC was increased by UP.' f e r t i 1 is ition . .1 application reduc’d organic carbon and P ‘./hale- i t i.nere -Scd ^>oil M, h and oH. P appl ication increased o i l d, K and pH. ‘V. ipol icat ion incr*. ia«_ , roi l H, h and oH wher>- as i c r c r\ v c c r: o i l P • rj ind P f spons r, r*. curvul in«. ar while not as i u ■ esnonrs v m Jincir. rhc od.imuni of U and P r , pc-j/trr ,./y ai re no-. c t ivt 1 y . M ixvv.um income W L. 1. ' - * * r t ' l i - r r l In lie 1 IV- r r . r
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    ThesisItemOpen Access
    Effect of continuous N P K Fertilization on the growth and yield behaviour of coconut with special reference to potash nutrition and its interrelation with other mineral nutrients
    (Department of Agronomy, College of Agriculture, Vellayani, 1985) Pushpangadan, K; KAU; Sadanandan, N
    At the Coconut Research Station , Balaramapuram in Trivandrum District of Kerala State an experiment was laid out in 1964 to assess the growth characters, yield attributes and yield of coconut variety West Coast Tall. The study was further enlarged to include the critical levels of leaf nutrient concentration as related to yield and the soil fertility statusdue to continued NPK fertilization . The treatments consisted of three levels of N, P and K (N-0, 340, and 680 g;P-0, 225 and 450 g and K-0, 450 and 900 g per palm per year). The experiment was laid out in a 3 raise to 3 partially confounded factorial design with two replications. Application of N enhanced the growth characters viz., production of female flowers, percentage fruit set, yield of nuts, weight of nuts, mean thickness and weight of meat, weight of copra and oil percentage. However the effect of N was found to be quadratic at the highest level applied. Application of P although improved the female flower prodcuction, its effect was negative towards copra weight and oil percentage . For the remaining characters studied, the initial level of 225 g per tree per year was found to be adequate.
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    ThesisItemOpen Access
    Ecophysiology of azolla and its management for rice production
    (Department of Agronomy, College of Agriculture, Vellayani, 1985) Alexander, D; KAU; Sadanandan, N
    In order to explore the agronomic potential of azolla for rice production, an investigation entitled 'Ecophysiology of azolla and its management for rice production ' was carried out at the Regional Agricultural Research Station, Pattambi, during the years 1980 to 1984 with the following objectives: (1) To study the influence of environmental conditions on the growth and establishment of azolla. (2) To assess the nutritional requirement of azolla. (3) To find out the time of application and optimum quantity of azolla inoculum required for growing it as an intercrop with rice. (4) To identify the geometry of planting rice favouring the multiplication of azolla in the field.
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    ThesisItemOpen Access
    Evaluation of lowcost agronomic techniques for sustained rice production
    (Department of Agronomy, College of Horticulture, Vellenikkara, 1985) Sreedevi, P; KAU; Sreedharan, C
    Three field experiments were conducted at the Regional Agricultural Research Station, Pattambi, Kerala to evaluate some of the low cost agronomic techniques for sustained rice production during the period from 1982 to 1985. In the first experiment the performance of IR 42, a rice variety suited to low fertility conditions was assessed under varying levels of nutrition and spacing. Fertilizer, age of seedlings and planting density, for IR 42 were the experimental variables for the second experiment. In the third trial, azolla was evaluated as a low cost biofertilizer for IR 42. The first and third trials were laid out in split plot design while the second trial in factorial RBD. The rice cultivar IR 42 proved its mettle under the low fertility conditions. In fact, it gave an average yield of 2.78 t ha-1 in virippu and 2.32 t ha-1 in mundakan without any fertilizer application. A plant population of 33 hills m-2 (spacing 20 x 15 cm) in conjunction with full dose of fertilizer of 90 : 45 :45 kg NPK ha-1 recorded substantially more grain yield of 4.24 and 3.20 t ha-1 in virippu and mundakan seasons, respectively. Relatively lower grain and straw yields were registered by the treatment 100 hills m-2 (spacing 20 x 5 cm) at all levels of fertilizer application. The net return and benefit cost ratio were more in the former combination. Increasing the seedling number hill-1 from two to four or six was also found to be beneficial for this variety. At lower levels of fertilizer six seedlings hill-1 recorded higher grain yields. However, at higher levels four seedlings hill-1 was found to be superior. During virippu season planting of 35 days old seedlings was found to perform better compared to 30 and 25 days old seedlings whereas in mundakan season, 30 days old seedlings were found preferable in terms of grain yield. Recommended dose of fertilizers (90 : 45 : 45 kg NPK ha-1) with azolla @ 10 t ha-1 and 75 per cent of the same with azolla @ 15 t ha-1 recorded similar grain yields indicating that an extra dose of 5 t of azolla ha-1 could substantially reduce the chemical fertilizer requirement and save as much as 25 per cent of the fertilizer. The benefit cost ratios were almost equal in both the combinations while the return per rupee invested was more in the latter combination. The finding appears to caution against excessive use of azolla expecting better exploitation of all the benefits attributed to it. Nevertheless, data on the residual fertility of the soil after each crop indicate that residual fertility was higher in the plots receiving full dose of fertilizer along with the highest level of azolla, 20 t ha-1.