Crop Phenology

PHENOLOGY IS THE OBSERVATION AND MEASUREMENT OF EVENTS IN TIME

Introduced in 1853 by the Belgian botanist Charles Morren and is derived from the Greek words phaino, meaning “to appear, to come into view” and logos, meaning “to study.”

Phenology is the science that measures the timing of life cycle events for plants, animals, and microbes, and detects how the environment influences the timing of those events. In the case of flowering plants, these life cycle events, or phenophases, include leaf budburst, first flower, last flower, first ripe fruit, and leaf shedding, among others.

For example, a phenologist can record the dates that a plant opens its first and last flowers (from which the duration of flowering can be calculated), as well as the number of flowers that are open each day or week during the flowering period.

Variation in phonological patterns

Ideotype

• Donald (1968): Ideotype is a biological model which is expected to perform or behave in a particular manner within defined environment.• Donald & Hamblin (1976): gave concept of Isolation ideotype,

competition ideotype and crop ideotype.• Other ideotypes: Market ideotype, climate ideotype, stress ideotype,

pest ideotype, disease ideotype.

• Isolation ideotype: perform better when grown in isolation. Eg wide spacing.• Competition ideotype: perform well in genetically heterogenous

population.• Market ideotype: depends on market demand (quality). Eg. Seed

colour, size, paletibility..• Climate ideotype: related to abiotic and edaphic factors.• Stress ideotype: biotic+ abiotic stress

New plant ideotype• Consider the effect of changing climate and nature of biotic and abiotic stress.• NPI (Japonica Rice): Peng et al. (1993), IRRI developed Ist generation NPI low tillering with 3-4 panicle/plant under direct seedingNo unproductive tillersSturdy stem, thick and erect leaves200-250 grains/paniclePlant height: 90-100 cm, vigorous root systemMultiple IP&D resistanceDuration: 120-130 days; HI= 0.6 or 60 %Yield potential: 13-15 t/haGrain yield was not high as expected due to poor biomass production & poor grain filling which

led to II generation NPI

Peng & G S Khush (2003) developed IIst generation NPI (Ist generation × Indica)

• 330 panicle/m-2, 150 spikelets/ panicle• Grain filling: 80 %; Grain wt.: 25 mg/grain• Total biomass above ground: 22 t/ha• Grain yield: 11 t/ha• HI: 50 %

S up er Rice m od e l(Yu an , 2 0 01 )

• Plant height 100 cm; culm length 70 cm• Moderate tillering with 270-300 panicle m-2 & panicle wt. : 5 g• Flag leaf length: 50 cm & located 20 cm higher from top panicle• Leaf width 2 cm; narrow & V shaped leaf• LAI: 6; • HI: 60%• Leaf area: grain wt. :: 100 : 2.2-2.3

Lowland rice Upland rice Rain fed rice

6-10 panicles/hill 5-8 panicles/hils 5-7 panicles/hill

150-200 grains/panicle 150-200 grains/panicle 150-200 grains/panicle

130 cm plant height 130 cm plant height More

120-150 days duration 100 days duration --

Strong grain dormancy

Erect-moderate droopy leaf

Upper leaf erect & lower droopy

Long erect leaf

Yield: 5-7 t/ha Yield: 3-4 t/ha Yield: 4-5t/ha

Maize (Mock and Pearce)

• Stiff vertically oriented leaf above the ear and horizontal below the ear• Maximum p/s efficiency and efficient conversion of photosynthate to

grain• Short interval b/w pollen shed (anthesis) to silking• Small tassel size & more cob/ plant• Photoinsenstive• Cold tolerance• Long grain filling period and slow leaf senescencee

Wheat • Short and strong stem• Erect leaves and few small leaves• Presence of awn; large ear• Photo period insensitive• Double rust resistance• Early flowering and longer grain filling• Larger flag leaf• More tiller/area• High HI and yield

Brassica sp. Bhargwa et al.; 1984

• Plant ht. 1-1.25 m• 5-6 primary branches at 40-45 ° angle• Deep root system• 20 seeds/siliqua• Low dark respiration rate• High nitrate reductase activity• Main stem should bear maximum siliquae (40)• Lower three branches should have less siliquae (15)

Pulses • Determinant growth• Yield attributing characters should be high• Less anti-nutritional factors viz. Aflatoxin in GN• Synchronous growth • Resistant to biotic and abiotic stress• High yield