Field Crop

Stage 1: GERMINATION/SEEDLING

During the germination stage, adequate temperature and moisture are needed for wheat seeds to germinate. Wheat seeds enjoy an optimum temperature between54° and 77°F. Under favorable conditions, seedling emergence usually occurs within seven days. Until the first leaf becomes functional, the seedling will depend on energy and nutrients stored in the seed.

Stage 2: TILLERING & STEM EXTENSION

The next stage is tillering. Tillering usually starts when plant has 3-4 leaves. After the wheat plant finishes forming tillers, it begins elongation of its internodes or the stem extension stage of growth. The boot stage begins when the head begins to form inside the flag leaf.

Stage 3: HEADING & FLOWERING (POLLINATION)

Next is heading where the head will fully emerge from the stem. After this take places, the plant starts reproductive growth or flowering. Pollination is normally very quick, lasting only about three to five days. Wheat is self-pollinated and it is during this time that kernels per head are determined by the number of flowers that are pollinated. High temperatures and drought stress during heading and flowering can reduce kernel numbers or yield.

Stage 4: RIPENING& MATURITY

After pollination, the ripening stage begins. Ripening is divided into four levels of maturity: milk, soft dough, hard dough, and finally mature. It is during this time that the wheat plant turns to a straw color and the kernel becomes very hard. Harvest can begin when the grain has reached a suitable moisture level.

Rice plants take around 3–6 months to grow from seeds to mature plants, depending on the variety and environmental conditions. They undergo three general growth phases: vegetative, reproductive, and ripening.

Rice varieties can be categorized into two groups: the short-duration varieties which mature in 105–120 days and the long-duration varieties which mature in 150 days. A 120-day variety, when planted in a tropical environment, spends about 60 days in the vegetative phase, 30 days in the reproductive phase, and 30 days in the ripening phase.

Stage 1: Germination

Germination in rice occurs when the first shoots and roots start to emerge from the seed and the rice plant begins to grow.To germinate, rice seeds need to absorb a certain amount of water and be exposed to a temperature range of 10–40 °C. This breaks the dormancy stage of the seed. When planted into flooded soil, the shoot is the first to emerge from the seed, with the roots developing when the first shoot has reached the air. If the seed is planted in non-flooded soil, the root is the first to emerge from the seed and then the shoot.

Stage 2: Vegetative phase

The vegetative phase is characterized by the development of tillers and more leaves, and a gradual increase in plant height. The number of days the vegetative stage takes varies depending on the variety of rice, but is typically between 55 and 85 days. The seedling stage starts right after the first root and shoot emerge, and lasts until just before the first tiller appears. During this stage, seminal roots and up to five leaves develop. As the seedling continues to grow, two more leaves develop. Leaves continue to develop at the rate of one every 3–4 days during the early stage. The late vegetative phase starts when tillering begins, which extends from the appearance of the first tiller until the maximum number of tillers is reached. This typically happens 40 days after sowing. The stem begins to lengthen late in the tillering stage and stops growing in height just before panicle initiation about 52 days after sowing, which also signals the end of the vegetative phase.

Stage 3: Reproductive phase

The first sign that the rice plant is getting ready to enter its reproductive phase is a bulging of the leaf stem that conceals the developing panicle, called the ‘booting’ stage. Then the tip of the developing panicle emerges from the stem and continues to grow. Rice is said to be at the ‘heading’ stage when the panicle is fully visible. Flowering begins a day after heading has completed. As the flowers open they shed their pollen on each other so that pollination can occur. Flowering can continue for about 7 days.

Stage 4: Ripening phase

The ripening phase starts at flowering and ends when the rain is mature and ready to be harvested. This stage usually takes 30 days. Rainy days or low temperatures may lengthen the ripening phase, while sunny and warm days may shorten it. The last three stages of growth make up the ripening phase.

Ripening follows fertilization and can be subdivided into milky, dough, yellow, ripe, and maturity stages. These terms are primarily based on the texture and color of the growing grains. The length of ripening varies among varieties from about 15 to 40 days. Ripening is also affected by temperature, with a range from about 30 days in the tropics to 65 days in cool temperate regions.

Vegetative Growth Stages

The Vegetative Growth Stages consist of the Emergence Stage, the Leaf Stages and the Tasseling Stage:

• Emergence Stage (VE)
• Leaf Stage (Vn)
• Tasseling Stage (VT)

Emergence Stage (VE)

During this stage most of the growth remains below the soil surface. This protects the seed from potential late frost. Soil moisture is important but more importantly is the timing of the planting, the later the planting the lower the yield potential. Below is a chart of general planting dates. These dates will vary as you move north and south of the Corn Belt.

Leaf Stages (Vn)

The leaf stages are based on the number of leaves (n) on the corn plant. Each leafing stage carries its own significance.

V5 – Occurs 14 days after Emergence. Cooler soil temperatures will delay the plant from reaching this stage as well as delaying tassel formation. It will not affect yield, it could lead to a late harvest and a potential of frost damage before harvest.

V9 – Occurs 28 days after Emergence. Flooding at this or earlier stages is a concern as it can kill the plant within a few days. Flooding at later stages is less detrimental because most of the growing is above ground.

V15 – Occurs 56 days after Emergence. Moisture is critical from the V6 – V15 stage. Extended drought can reduce the yields by as much as 25%.

Tasseling Stage (VT)

The tassel is completely visible when the plant has reached its full height and will begin to shed its pollen. Hail damage is more serious at this time than any other growth period.

Reproductive Growth Stages

There are six stages to the Reproductive Growth Stages:

• Silking
• Blister
• Milk
• Dough
• Dent
• Maturity

Silking

Occurs about 3 days after the Tasseling Stage. Silk is visible outside the husk. Falling pollen grains are captured by the silk and grow down the silk.

Blister

Occurs 10 – 14 days after Silking. Between the final growth stage and Blistering moisture is critical. Drought conditions can reduce yield potential by as much as 50%, or 60% per day during a drought.

Milk

Occurs 20 days after Silking. Stress effect is less now. Kernels are beginning to yellow outside and contain a milky white inner fluid (80% moisture level).

Dough

Occurs 26 days after Silking. Kernels begin to gain in dry weight and size and have a ‘doughy’ consistency. An early frost at this stage can be detrimental to the crop with a potential loss of 50%.

Dent

Occurs 36 days after Silking and should finish about 48 days after Silking. The kernels begin to dry and have a dented appearance. Stress at this point will reduce kernel weight but not kernel number. Frost is the major concern because it can stop dry matter accumulation and cause premature black layer formation, reducing yield.

Maturity

Occurs 55 days after Silking. All kernels have attained maximum dry weight. Husks and many leaves are no longer green.

Stage 1: Crown Planting

Pineapples grow from the crowns produced by the fruits, or from offsets produced around the base of a mature plant. Remove the leafy fruit crown and cut away the fruit and lower foliage to leave the stringy fruit core and top leaves. This will send out roots and become a new plant. You must plant the crown in moist but well-drained soil for it to form roots and grow. It can take the crown six to eight weeks before it roots and begins putting on new growth

Stage 2: Foliage and Root Growth

The new plant forms roots first. New foliage growth starts once the pineapple has developed a root system and begins taking in moisture and nutrients from the soil. The best foliage and root growth occurs in evenly moist soil. The plant needs all-day sunlight and a temperature range between 65 and 85 degrees Fahrenheit to remain healthy and growing.

Stage 3: Flowering and Fruiting

The pineapple plant only flowers at full maturity, which can take two to three years. Pineapples, especially those grown as houseplants, may be reluctant to flower and set fruit. The fruit begins to form after flowering and is ready to harvest once the scales turn from green to golden yellow.

Stage 4: Offsets

Each pineapple plant can only flower and fruit once, but the main plant usually produces offsets once it begins to flower. These offsets, which are small plants growing off the main plant, can then grow into mature plants and produce their own flowers and fruits. Leave the offsets on the plant until after you harvest the pineapple and the main plant begins to decline. You can then cut them free from the main plant's root system and grow them to maturity in their own individual pots.