Assessment Schedule: Agricultural and Horticultural Science: Demonstrate knowledge of horticultural plant management practices and related plant physiology (90924)

Evidence Statement

Question One – Weed control

Not Achieved	Achievement	Achievement with Merit	Achievement with Excellence
Describes horticultural plant management practices and related plant physiology and / or growing conditions.	Links ideas to explain why horticultural plant management practices, or steps within practices, are carried out.	Applies knowledge of horticultural plant management practices to given situations. This may involve comparing and contrasting or justifying management practices.
N1	N2	A3	A4	M5	M6	E7	E8
Describes ONE idea at the Achievement level.	Describes TWO ideas at the Achievement level.	Describes THREE ideas at the Achievement level.	Describes FOUR ideas at the Achievement level, including at least ONE Explained idea	Explains THREE ideas at the Merit level.	Explains FOUR ideas at the Merit level.	Justifies the method chosen.	Fully justifies the method chosen by comparing and contrasting.

Examples of evidence for answers

In (a) describes the plant structures. (Achievement :3/5 required- both correct name and correct function needed). For example: A Cuticle/epidermal cells Protect leaf cells from water loss/pest and disease invasion B Xylem vessels Carry water from root to leaf C Palisade cells Contain a lot of chloroplasts- close to leaf surface to catch the most light D Spongy mesophyll Air spaces aid in gas exchange E Stomata Hole on the leaf underside for control of exit and entry of water vapour and in gas exchange. In (b) describes the requirements of photosynthesis (2/3 required for Achievement) Water, carbon dioxide, sunlight, chlorophyll. In (c ) describes one difference between respiration and photosynthesis for Achievement e.g. Photosynthesis requires energy, photosynthesis releases energy. Could also describe the different reactants and products.
In (d i) describes (Achievement) / explains (Merit) the effects that weeds have on plant processes required for vegetable production: Weeds grow fast, blocking light to the plant (Achievement) and reducing the plants’ ability to photosynthesise (Merit). Weeds compete for nutrients, so the plant gets less of these (Achievement) and chemical processes do not occur as quickly (Merit). Weeds can harbour pests which suck the sap from the plant (Achievement), reducing the amount of glucose for the plant to convert to energy through respiration (Merit). Weeds can create a more humid environment conducive to disease development (Achievement), which reduces the photosynthetic area of the leaves (Merit). Weeds compete for growing space (Achievement), so the plant product may be distorted in shape (Merit). Weeds compete for water (Achievement), which is a raw material of photosynthesis (Merit). Total of two A and/or M grades available

In (d ii) describes / explains / justifies either chemical or physical control over the other control method (2 of each grade available)

Chemical control Advantages It is quicker, and therefore reduces labour costs. Systemic herbicides kill the whole plant, whereas physical weeding can pull the leaves off, leaving the root to re-grow. Effective when large-scale control is required.	Physical control Advantages It can be done selectively around desirable plants, so they are not damaged or killed. Effective immediately. Can ensure all tap roots are removed.
Disadvantages Spray drift can damage desirable plants. Application requires calm conditions without imminent rain. Slower to take effect.	Disadvantages Labour-intensive and time-consuming. Lazy weeding can result in living parts of the weed re-growing. Needs to be done regularly.

Question Two – Irrigation

Not Achieved	Achievement	Achievement with Merit	Achievement with Excellence
Describes horticultural plant management practices and related plant physiology and / or growing conditions.	Links ideas to explain why horticultural plant management practices, or steps within practices, are carried out.	Applies knowledge of horticultural plant management practices to given situations. This may involve comparing and contrasting or justifying management practices.
N1	N2	A3	A4	M5	M6	E7	E8
Describes ONE idea at the Achievement level.	Describes TWO ideas at the Achievement level.	Describes THREE ideas at the Achievement level.	Describes FOUR ideas at the Achievement level, including at least ONE Explained ideas and at least ONE Described idea.	Explains THREE ideas at the Merit level.	Explains FOUR ideas at the Merit level.	Justifies the method chosen.	Fully justifies the method chosen by comparing and contrasting.
Examples of evidence for described answers may include: In (a) describes the plant structures involved in transpiration -describes three functions of water in plants. In (b) describes the impact of irrigation on plant growth -the benefits of one irrigation system. Examples: Plants have root hairs which absorb water. Inside the plant, xylem vessels allow the transport of water through the plant which exits out of the stomata pores. Functions of water include support, transport, involvement in chemical processes, and cooling. Irrigation will allow the plants to carry out photosynthesis during the drier summer months. Drip-line irrigation delivers water right to the root zone where it is needed.	Examples of evidence for explained answers may include: In (a) -explains in depth how plant structures are involved in transpiration -explains in depth three functions water has for plants. In (b) explains in depth the impact of irrigation on plant growth -the benefits of one irrigation system. Example: Plants have root hairs which absorb water from the growing medium (soil). These are very fine, hair-like structures which increase the effective surface area of the roots within the soil, enabling water to be absorbed more efficiently. Inside the plant, xylem vessels allow the transport of water through the plant. Water is sucked up the plant because of the evaporation of water through stoma in the leaves. This pulls water into the root hair so as to replace the water exiting via the stomata pores. Functions of water include: Support – plant cells that are full of water are turgid; they are thus pressed tightly against one another, which holds the plant upright. Transport – dissolved salts (nutrients) are transported in the xylem as water moves through the plant. Chemical processes – many plant processes require water for chemical reactions such as photosynthesis. Cooling – the evaporation of water from the leaves takes away latent heat from the plant. Irrigation will allow the plants to carry out photosynthesis during the drier summer months. Drip-line irrigation delivers water right to the root zone where it is needed, and will not be evaporated. This is because the water is not blown around or exposed to too much sunlight.	Examples of evidence for justified answers may include: In (b) justifies the selection of either overhead or drip-line irrigation, by comparing and contrasting the benefits in terms of impact on plant growth and health. Example: Selected management practice: Drip-line irrigation Irrigation will allow the plants to carry out photosynthesis during the drier summer months. Drip-line irrigation would be better than a pop-up system, because it will deliver water right to the root zone where it is needed. Water sprayed above ground by pop-up sprinklers is spread more widely than is needed, so is less efficient. Water droplets on leaves and petals can cause blemishes from sun-scorch marks, resulting in unattractive plants and flowers. This does not happen with drippers. Plant physiology must be referred to in the answer, or the intent of the standard is not followed. E7 – Clear justification for chosen technique. E8 – Comparison of two techniques.

Question Three – Nutrient application

Not Achieved	Achievement	Achievement with Merit	Achievement with Excellence
Describes how nutrient application practices are carried out.	Links ideas to explain why tomato production practices, or steps within practices, are carried out.	Applies knowledge of tomato production practices to given situations. This may involve comparing and contrasting or justifying management practices.
N1	N2	A3	A4	M5	M6	E7	E8
Describes ONE idea at the Achievement level.	Describes TWO ideas at the Achievement level.	Describes THREE ideas at the Achievement level.	Describes FOUR ideas at the Achievement level, including at least ONE Explained ideas and at least ONE Described idea.	Explains THREE ideas at the Merit level.	Explains FOUR ideas at the Merit level.	Justifies the method chosen.	Fully justifies the method chosen by comparing and contrasting.

Examples of evidence for answers may include:

Describe (Achievement) e.g. Nitrogen (A) This is needed for leaf and stem growth in the early stages(M) Soil should be moist (A)to aid dissolving of fertiliser and nutrient absorption (M) Even spread achieved by split application in different directions if using hand application or by use of spinning device or calibrated spreader.(A) This is done to make sure that all areas are covered with a density of fertiliser suitable for growth- not too concentrated that could cause plant wilting/root burn, and not too little to have a limited affect on growth.

Fertiliser can be applied in a solid form or through the irrigation system. Select and justify (Excellence) the best management practice by comparing and contrasting it with the other management practice Solid form Advantages Slow release, so the time between applications is greater. Soil acts as a nutrient buffer, so application doesn’t require such close monitoring. Doesn’t require complicated monitoring equipment. Through the irrigation system Advantages The effect of nutrient application is very quick. Application is easy. Dispersal of the nutrients is even. A more even application of nutrients to the soil for plants. Disadvantages Nutrients may be depleted from the soil between applications of fertiliser. Extra machinery such as trucks, or equipment such as fertiliser spreaders on ATVs, are required to apply solid fertiliser, or it must be applied by hand, which is time-consuming. Needs to be dissolved before being absorbed by plants. Disadvantages Nutrient levels in the irrigation water need to be frequently monitored. Fertiliser quantities need to be measured precisely, because there is no soil to act as a buffer to hold or release nutrients. – one point described (M)- one point explained E7 – Clear justification for chosen technique. E8 – Comparison of two techniques.

Judgement Statement

Not Achieved	Achievement	Achievement with Merit	Achievement with Excellence
0 – 6	7 – 12	13 – 18	19 – 24