MSc

ABSTRACT
The study entitled “Growth and productivity of aerobic rice (Oryza sativa L.) as
influenced by pink pigmented facultative methylotrophs (PPFM)” was undertaken at
College of Agriculture, Vellayani, during 2018 – 2020. The main objectives were to study
the effect of PPFM on rice seedling emergence and vigour, to assess its effect on growth
and yield of aerobic rice and to work out the economics.
The study was carried out as two experiments at the Integrated Farming System
Research Station, Karamana, during December, 2019 to April, 2020. The test variety of
rice was Uma (MO 16). The first experiment was a pot culture study in completely
randomised design with six treatments and four replications. The treatments comprised
seed treatment of rice with five superior isolates of PPFM from the Department of
Agricultural Microbiology (T1 - PPFM 16, T2 - PPFM 26, T3 - PPFM 35, T4 - PPFM 37,
T5 - PPFM 38) and T6 - control (distilled water).
The second experiment was conducted to assess the effect of the five PPFM
isolates on growth and yield of aerobic rice. The experiment was laid out in randomised
block design with [(5 x 2) + 2] treatment combinations, replicated thrice. The treatments
were the five PPFM isolates (p1 to p5) and two methods of application, viz., m1 – seed
treatment (1%), m2 – seed treatment (1%) + foliar application (2%) at 30 and 50 days
after sowing (DAS), compared against two controls (c1 – KAU POP, c2 – KAU POP +
water spray at 30 and 50 DAS).
The results of experiment I revealed uniform effect of PPFM isolates on
emergence percentage. However, emergence rate index (ERI) was the highest for PPFM
38 (160), followed by PPFM 37 (156). Seed treatment of rice with PPFM 38 recorded
significantly longer seedling roots, higher seedling dry weight and greater seedling vigour
index I. Seedling vigour index II was higher for seeds treated with PPFM 37.
The results of experiment II showed that among the PPFM isolates tested, PPFM
38 (p5) resulted in taller plants, more number of tillers per square metre, leaf area index,
dry matter production, root shoot ratio and yield attributes. However, root volume of rice
was observed to be higher with PPFM 16 and remained at par with PPFM 38. Grain yield
(4.43 t ha-1), straw yield (5.31 t ha-1) and harvest index were also superior with PPFM 38.
Between the two methods of application, treating rice seeds with PPFM (1%) +
foliar application (2%) at 30 and 50 DAS (m2) elicited superior effect on growth
attributes including dry matter production and yield attributes like productive tiller count,
grain weight per panicle and straw yield . However, root volume was not affected by the
method of application of PPFM. Growth and growth attributes and yield attributes and
yield were superior with the treatment combination p5m2 (PPFM 38 as seed treatment +
foliar application). Sterility percentage was significantly lower (13.94%) with seed
treatment of PPFM 16 (p1m1), and it was on par with p5m2.
Between the controls, KAU POP (c1) was significantly superior to KAU POP +
water spray (c2) with respect to growth and yield. PPFM treatment was superior to both
the controls. However, the mean grain weight per panicle and mean grain yield recorded
by the treatments were comparable with that of KAU POP.
Chlorophyll content and proline accumulation recorded at panicle initiation and flowering
stages were significantly higher with PPFM 38. Seed treatment (m1) recorded superiority
in proline content. The treatment combination, p5m2 recorded significantly higher
chlorophyll and proline at both the growth stages. While KAU POP (c1) recorded higher
chlorophyll content, proline accumulation was greater with KAU POP + water spray (c2).
Nutrient uptake followed the same trend as dry matter production.
Gross returns, net returns and B:C ratio were significantly higher for treatment
with PPFM 38. The effect of method of application was not significant. The treatment
combination p5m2 resulted in better economics. Mean gross returns of treatments and
KAU POP was comparable. However, net returns and B:C ratio were significantly higher
for the treatments. The present study revealed that treating rice seeds with PPFM 38 (p5)
at 1 per cent resulted in vigorous seedlings as evidenced by superior seedling characters.
Seed treatment (1%) followed by foliar application (2%) of PPFM 38 (p5m2), twice, at 30
and 50 days after sowing enhanced the growth, yield and economics of aerobic rice.